1. Field of the Invention
The present invention relates to a disk player, and more particularly, to a disk player which can play both an audio disk and a memory disk.
2. Description of Background Information
A disk player, adapted to be mounted in a vehicle, to play a digital audio disk (hereafter referred to simply as xe2x80x9caudio diskxe2x80x9d) or a so-called CD (compact Disk) is designed to function as follows. After the disk is loaded into a play position, various types of servo systems will be invoked to provide playable circumstances. It is then determined, for example, whether or not the disk to be played this time is the same as the previous one. If the disk is the same, it will be played starting at the last address of the previous playing; if not, the disk will be played beginning with the first piece of music.
While the disk player is installed in a vehicle as one of on-vehicle devices, a so-called navigation system has recently been developed. The navigation system has a so-called CD-ROM having map data stored therein. This system reads map data of the desired map from the CD-ROM, and supplies the data as a display information signal to a display. As a result, the map is shown on the display so that a user can acknowledge or confirm the present location of the vehicle. Since the CD-ROM (hereafter referred to as xe2x80x9cmemory diskxe2x80x9d), a medium to store map data, has the same signal format as the CD, both the audio disk and memory disk are playable by a single disk player.
With the memory disk in use, when the disk player receives a read command for the map data of the desired map from a system controller, the player, responding thereto, needs to shift to an operation to read map data at the designated address. Therefore, if the memory disk, when loaded to the play position, is accessed to immediately start playing with the first music piece or at the last address as in the case of the audio disk, a pickup position will change before the read command is received from the system controller. It therefore inconveniently takes time to search for the head address of the required map data after reception of the read command.
An on-vehicle multisource reproducing device with multiple audio sources, such as audio disk player and AM/FM tuner, is designed to give priority to the display player such that when a disk is loaded into the disk player while another source other than the CD is being played, a reproduction signal of the disk player is automatically selected upon completion of the loading of the disk to the play position, and is then fed to a loudspeaker.
Suppose the disk player for both audio and memory disks is installed as one of the multiple audio sources in the on-vehicle multisource reproducing device. Then, if the reproducing signal of the disk player is selected immediately after the memory disk is loaded to a play position to display the map during playing a source other than the CD, as per the prior art as mentioned above, there will arise a problem that if one has been listening to the AM/FM tuner, the reproduced tone will pant.
On-vehicle single disk players to play the audio disk are so designed as to execute auto-repeat play. In other words, in sequential play mode where the disk player sequentially plays pieces of music from the first piece, when all pieces are played, the operation will automatically return to the first piece to repeat the playing. There is a so-called multidisk player which stores multiple CDs (six CDs, for example) and selectively plays one of them. In sequential play mode, this multidisk player changes a disk with another when each disk is played through to start with the first piece of the new disk. In random play mode, on the other hand, when one music piece is played through, the multidisk player produces the disk number and track number of the next music piece to be played using random numbers, to start playing that piece.
As described earlier, with the memory disk in use, when the disk player receives a read command for the map data of the desired map from a system controller, the player should execute an operation to read map data at the designated address. Therefore, in an audio/memory disk player, when a special play mode, such as auto-repeat play or random play is set, a pickup position will change before the read command is received from the system controller if the special play mode is executed in playing the memory disk in the same way as done for the audio disk. When another piece of map data is to be read out after reading the map data of one map, therefore, it inconveniently takes time to search for the head address of the desired map data after reception of the read command.
A so-called magazine-disk player is known which selectively plays one of multiple (six, for example) CDs stored in a retractable/protrudable manner in a case called xe2x80x9cmagazinexe2x80x9d that is loaded detachably in the player.
There is a system already known which selectively plays one of multiple disks by remotely controlling the magazine-disk player arranged in a suitable location in a vehicle (e.g., in the trunk).
Accordingly, when the magazine-disk player is installed in a vehicle with audio CDs and memory disks loaded in the magazine, reproduction of musical tones and map display can selectively be performed.
In such an audio disk/memory disk player, if no muting is executed at the time of playing a memory disk, the map data on the memory disk will be released as noise from a loudspeaker. Even if the muting process is carried out, when a user erroneously acknowledges the memory disk as an audio disk and gives an operation command for audio disks such as random play, the moving of the pickup will be executed in the same manner as done for audio disks with no sounds generated from the loudspeaker. The user may therefore feel strange.
A disk player, which can play both an audio disk for sound reproduction and a CD-ROM (memory disk) having map data or the like for the navigation system recorded thereon, includes a D/A converter to convert a decoded digital signal into an analog signal when the audio disk is played. When the memory disk is played by such a disk player, the digital signal is supplied to a loudspeaker through a signal processor including the D/A converter, thus producing unpleasant noise. To prevent this shortcoming, a mute circuit may be provided to inhibit the supply of the signal from the D/A converter to the next stage.
If this measure is taken to prevent noise generation, the supply of the digital signal to the D/A converter will not be stopped, causing wasteful power dissipation due to the continuing conversion operation of the D/A converter.
Considering the above, it is therefore a primary object of the present invention to provide an audio disk/memory disk player capable of rapidly searching for the specified address in a case of the memory disk being played.
Another object of the present invention is to provide an on-vehicle multisource reproducing device which can properly control the supply of a reproduction signal to a loudspeaker in accordance with the type of a disk to be played.
It is a further object of the present invention to provide an improved audio disk/memory disk player which overcomes the above-described problems of the conventional magazine-disk player.
It is a still further object of the present invention to provide a disk player which saves electric power to be wastefully consumed in a D/A converter when the memory disk is played.
An audio disk/memory disk player according to the present invention comprises: means for performing such control as to start playing a disk in response to a command; discriminating means for determining if a disk to be played is an audio disk or a memory disk; and means for performing such control as to play a music starting with a predetermined piece of music when the discriminating means judges that the disk to be played is the audio disk, and to set a pause mode when the disk to be played is judged as the memory disk.
This audio disk/memory disk player of the present invention determines whether the disk to be played is an audio disk or a memory disk at the time the disk is played, and enters the pause mode in case of the memory disk.
According to another aspect of the present invention, an on-vehicle multisource reproducing device, which has multiple audio sources including a disk player as one audio source and a selecting means for selecting one of reproduction signals from the audio sources and supplying the selected reproduction signal to a loudspeaker, comprises: means for detecting that loading a disk to a play position is complete and for generating a loading complete signal; control means for starting playing the disk in response to the loading complete signal; discriminating means for determining if the disk being played is an audio disk or a memory disk; and means for sending a selection command to the selecting means to select the reproduction signal from the disk player only when the disk is judged by the discriminating means as the memory disk.
According to the on-vehicle multisource reproducing device of the present invention, after a disk is loaded to the play position in the disk player, the device will start playing the disk first, to determine whether the disk being played is an audio disk or a memory disk. Only when the disk is judged as the audio disk, the reproduction signal from the disk player is then selected, and is supplied instead of another source to the loudspeaker.
According to a yet another aspect of the present invention, an audio disk/memory disk player comprises: means for setting a special play mode; discriminating means for determining if a disk being played is an audio disk or a memory disk; detecting means for detecting that playing for a memory area of a series of group information is complete; and control means for performing such control that, with the special play mode set, the mode is changed to a pause mode at a time of playing the memory disk when the detecting means generates a detection output, and the special play mode is enabled only at a time of playing the audio disk.
In the audio/memory disk player of the present invention, when playing for the memory area of a series of group information is complete in special play mode set, the mode is changed to the pause mode when the played disk is a memory disk, while the special play mode is enabled only when the played disk is an audio disk.
The xe2x80x9cseries of group informationxe2x80x9d is audio information of one piece of music in case of the audio disk, and is a group of map data corresponding to a sheet of map in case of the memory disk.
According to a further aspect of the present invention, there is provided an audio disk/memory disk player which comprises: discriminating means for determining whether a disk is an audio disk or a memory disk; muting means for inhibiting generation of a sound from a loudspeaker based on a discrimination result from the discriminating means; and means for ignoring at least one of operation commands based on the discrimination result.
This audio disk/memory disk player of the present invention determines if the disk being played is an audio disk or a memory disk and, if it is a memory disk that is being played, executes a muting process to shut off a sound from the loudspeaker as well as to ignore at least one of operation commands.
According to a still further aspect of the present invention, there is provided a disk player having signal reading means for reading an information signal by rotating a loaded digital disk, decoding means for decoding the information signal, and signal processing means for reproducing a digital signal from the decoding means as an audio signal, which player comprises: detecting means for detecting that the loaded disk is a memory disk; and stop means for stopping supply of the digital signal from the decoding means to the signal processing means when the detecting means detects that the disk is a memory disk.
According to the above digital disk player of the present invention, when a loaded disk is played and detected as a memory disk, this digital disk player stops the supply of the digital signal from the decoding means to the signal processing means which reproduces the digital signal as an audio signal.